Medical devices are frequently used to treat the anatomy of patients. Such devices can be permanently or semi-permanently implanted in the anatomy to provide treatment to the patient. Endoluminal devices, such as for example stents, grafts, stent-grafts, filters, valves, occluders, markers, and therapeutic agent delivery devices, are inserted into the body at an insertion point and moved through a lumen to a treatment area using a catheter. Exoluminal devices, such as for example clips, rings, snares, staples, grafts, therapeutic agent delivery devices and the like, are inserted into a body cavity and implanted surgically or inserted and moved to a treatment site using an endoscopic tool. Exoluminal devices for repair or restriction of a body conduit, such as for example dilation or diameter restrictors, constrictors, cuffs, anastamoses, venous valve supports, devices for repairing arteriovenous malformations and trauma damage, and exovascular stents, can be fastened around the outside of the vessel at the repair site.
Medical devices such as exoluminal and endoluminal devices can be made partially or entirely of materials that are designed to degrade in the human body. In some instances, a medical device is needed only temporarily in the human body, and it can be more practical to design a device to degrade rather than try to remove it from the patient when it is no longer needed. For example, a medical device used to provide temporary support for a body conduit can be made from bio-corrodible metals, biodegradable polymers, or combinations of these materials. When such an implant partially or wholly disappears in vivo, it is said to have bio-corroded or biodegraded, or that it was absorbed by the body. The degradation products generated from the bio-corroding or biodegrading device can be biocompatible.
Although many advances have been made to medical devices in general, the deployment of an exoluminal or endoluminal medical device can be limited in range or stages of expansion or contraction or be too invasive for a particular therapy. Such deployment can be inherent to the design of a medical device. Additionally, a medical device can not have any ability to change its configuration, such as its physical dimensions, in the patient over time to address the patient's changing physiology or to provide a delayed or extended therapeutic procedure.
Therefore, new medical devices that are amenable to slow and controlled remodeling, or that change in configuration over extended periods of time in the patient, are desired.